Self regulating fluid pressure valve



Jan. 19, 1937. A. D. HARRISON Y u SEF REGULATING FLUID RESSURE VALVEFiled. Jari. 1 3, 1934 I F/G. 4.

ATTO/elven Patented Jan. 19, 1937 UNITED STATES PATENT OFFICE Albert DexHarrison, Hampstead, Quebec, Canada Application January 13, 1934, SerialNo. 706,504 In Canada January 14, 1933 4 Claims.

The invention relates to a self regulating iiuidy pressure valve, asdescribed in the present specification and illustrated in theaccompanying drawing that forms part of the same.

The invention consists essentially in the automatic readjustments andthe maintenance of pressures in the brake cylinder as pointed out in theclaims for novelty following a description in detail of the variousparts concerned in this invention.

The objects of the invention are to adapt the piston type of valve inthe control of the air iiow to the brake cylinder and in the exhausttherefrom to economize in the consumption of air and utilize the airconsumed to the fullest extent of its force in applying the shoes; toautomatically close the valve when and by reason of the air pressuredesired in the brake cylinder, thereby economizing in the use of air asaforesaid; to facilitate the application of the brakes and at the sametime operate the parts with exactitude and thereby eliminate to a greatextent the mistakes of a poor operator and the bad results of flatwheels; to eiect the emergency application without undue loss of air andcoincidently effect the sanding of the rails in tramcars and otherrail-Y way vehicles and to segregate the valves in this emergencyapplication, thus avoiding the use of the emergency brake without justcause; to alford accessibility to all the parts of the mechanism and todo away with gaskets. or other material, and generally to provide adurable, eicient and economical self regulating fluid pressure valve.

In the drawing, Figure 1 is an elevational View of the mechanism brokenaway to disclose a section of the manual operating lever and itsconnections.

Figure 2 is a plan view of the device.

Figure 3 is a cross sectional View on the line 3-3 in Figure 1.

Figure 4 is a cross sectionalview on they line 4-4 in Figure 1.

Like numerals of reference indicate correspending parts in the variousiigures.

Referring to the drawing, the numeral I5 indicates a valve mechanismbody in the form of a block having the passage I6 connected to thereservoir of compressed air, the passage I1 used in the serviceapplication or release of the brakes, thek passage I8 for the exhaust ofthe air,'the passage I9 for blowing in sanding operations and thepassage 20 used in emergency applications.

'I'he passages I6, l1, and I8 extend upwardly to the annular crosschannels 24, 25, and 26.

The valve chamber 21 in parallel form having the ports 28, 29, 30, and3l and closed at the end by the screw plug 32, is introduced in a bore33 through the block I5, this bore being concentric with the crosschannels 24, 25, and 26 and of lesser diameter thereby completing theannular channels or chambers encircling the valve chamber 28 andcommunicating therewith through said ports in the manner hereinafterdescribed.

The valve 34 operates in the valve chamber 21 and is formed with theannular ports 35 and 36 registering with various ports in the valvechamber 21 as explained in following the course of the air in theseveral operations, this valve being closed at one end by the screw plug31.

This `Valve 34 extends beyond the chamber 21, which in turn extendsbeyond the block.

The iloating lever 38 is pivotally connected to the valve at 39 and thisfloating lever is slotted inwardly from either end at 40 and 4Irespectively.

The operating handle 42 is xedly mounted on the spindle 43 and thisspindle is journalled in the bearing 44 set in the recess 45 andspring-held by the flange 46 at the lower end of the head 41 of thespindle by the spring 48, the cap 49 forming the stops 50 and5l closingin said flange in said recess.

The spindle 43 is reduced from the flange downwardly and its lower endforms the pinion 52 coacting with the rack 53.

The rack 53 slides inthe passage 54 parallel with the valve in the valvechamber 21, and this rack forms a socket 55 for the headed pin 56,spring-held by the spring 51 in said socket and carrying at its outerend the anged head 58 to which the pivot 59 is rigidly secured, thispivot extending upwardly through the slot 40 of the floating lever 38,thus any movement of the handle in the' operation of the brakes isimmediately communicated to the lever 38 through the rack 53 andresiliently mounted head 58.

The equalizing chamber 60 is also parallel to the valve chamber 21 onthe other side and the bellows form of diaphragm 6I operates in saidequalizing chamber 66, the heads 62 and 63 of this diaphragm beingmounted on the spindle 64, these heads being maintained apart by thespring encircling the said spindle.

The head 62 is xed on said spindle but held in a exible position subjecttothe air pressure by the bellows 6I connecting it to the head 63.

The head 63 is externally threaded andA screwed into the wall of theequalizing chamber 60 and internally threaded and screwed on to theslidable sleeve 61 mounted on said spindle.

The louter end of this spindle 64 carries a pivot pin 68 which extendsupwardly from the slot 4l and forms an adjustable fulcrum dependent forits position on the pressure which is connected to the brake cylinderthrough the passage 69 and to the service passage Il fed from thereservoir passage I6 through the movement of the valve 34 all thesedepending on the operation of the floating lever 38.

It will be noticed that to perform the sanding operation, that is toblow sand on the tracks, the air is fed through the passage- I 9 and tomake the necessary communications the valve 'l0 must be operated.

This valve 'l0 is contained in the .valve chamber l 1I, which is screwedinto the cavity 12 in the block and communicating with the recess 55.

The port 13 in the wall of the chamberl'l-I communicates with theannular channel 14, this in turn communicating with the emergencypassage 2).v The spring 'I5 encircles the valve lll and presses againstits head from thev valve chamber rcasing 1l, while the spring 'I6 iscontained within the cap ll closing the opening to'tlie'cavitylZ andengaging the iiange 'lsurrounding the valve 'i0 and xedly mountedthereon.

The inner end of this valve l projects into the socket 55 and is thereengaged by the inner end of the rack 53, the preliminary operation inrotatingthe handlev in that direction being the sanding of the vtracksthrough the' flow of air through the passage IS while the next operationto accomplish the application s of the service brakes is the furthermoving of the handle in the same direction, which connects the passage2U with thefport 13 throughthe valve chamber Wall and connecting" withthe annular chamber 14. i s

I n the operation of #theA invention, the first step is to turn thehandle for the purpose iof applying thebrakes. This turning vof thehandle is done comparatively slowly and over a radius marked off bygraduations.

A V'I'he movement along the path of the graduations is continuous untilythe handle reaches well on tothe end of the path, possibly aboutfthreequarters, and this is what they call the service application.

The result or this movement is the operation of the pinion on the'Vsteni ofthe handle, which coacts with the rack and this rack in turndraws the floating lever@ The iioating lever is temporarily fulcrumed onthe pivot at the outer end of the diaphragm spindle, and intermediatelyof this floating lever, the pivot at the end 'of the Vvalve stem isengaged by the iioating lever and the valve moved inwardly, and thismeans that the annular ports surrounding the valve register with theports in the valve casing and in turn, thesey ports in the valve casingregister with the annular chambers in'connection with the reservoirpassage "I6 and service passage Il respectively. Y

The result of this'operation is that Athe air from the vservicereservoir flows along 'the pas'- sage I6 into the annular chamber andthrough the port in the valve casing and corresponding annular port intothe interior of the valve through the port provided therefor, and thisair flows out through a port inthe wall of the valve into an annularport the'rearound' `and out through a port in the'valve casing to themiddle annular chamber and'from theredown through the service passage Ilto thebrake cylinder.

The result of this flow if it ended there, would be the application ofthe brakes, but there isa backflow from the brake cylinder to andthrough a passage to the diaphragm chamber and this has the effect ofcompression on the diaphragm, which moves it in opposition to thecompression of the spring, which in turn moves the temporary fulcrumhereinbefore mentioned, and consequently closes the valve ports.

The condition now is a service application with the air pressurebalanced between the diaphragm chamber, the service passage and thebrake cylinder, which remains governed entirely by the v'portion of thediaphragm, for if there is any .leak at all in the brake cylinder, thenthe movement of the diaphragm will again move the oating lever and avalve and admit fresh air, and during the period this pressure remainsthe brakes are applied in what is called the service application.

n AIn the beginning of the release operations, the handle is startedonthe return stroke and moves slowly tol or near the midposition and thistheir governs theflow of the air so that any quick release is avoided,and no jerk occurs, and from this midposition to which it is held, whilethe brakes'are still applied, it is moved `for the actual release to thestarting point.

' It will of course, be understood that while the car is standing thisnear midposition is the holding position, forv the car is then`stationary, following the rst movement, in other words, to apply thebrakes in theiirst place, the air pressure must be greater than merelyfor the holding of the car toA the'stationary position, the nal releasecornes after that. i

Meanwhile, the floating lever has assumed its different positions, andlikewise the fulcrum pivot has also assumed its different positions. Theoriginal fulcrum position of the diaphragm lever is when the diaphragmchamber is free from pressure, then in the service application, thediaphragm spindle :through the pressure of air behind the diaphragmmoves the diaphragm pivot to its service position, and again thefloating lever temporarily fulcrums on this diaphragm pivot when thehandle is moved back to the near midposition.

This movement of the handle draws on the valve outwardly through thevpivot connection, and the stern of said valve and uncovers the exhaustport which permits the flowof air from the midannular chamber or servicepipe or passage and `the exhaustl air iiows through the exhaust passageto the atmosphere.

This means that there is a'reduction of air in the brake cylinder, butthen there must'be'the equalizing of the pressure all around and theconsequence is that the pressure in the diaphragm ,chamber reduces,and'this means that thediaphragm pivot point engaged by the floatinglever, moves inwardly and consequently, the Valve moves inwardly andcloses the exhaust port and restores the brake application at a lowerpressure.

The further movement inwardly of the handle for the actual releaseAofthe brakes again moves the pivot ofthe rack outwardly tothe 01Tposition, and this again draws the stem of the valve outwardly andconsequently,` the valve, which uncovers the exhaust-port and releasesthe air from the brake cylinder and the diaphragmv chamber, and throughthe spring pressure the diaphragm spindle and diaphragm pivot, and theresult is that vthe valve is at its outermost position which uncoversthe exhaust port permanently and seals both the inlet' port from thereservoir and the outlet port from the brake cylinder.

The emergency application of the brakes means a continued movement ofthe handle beyond the service application position, and as a generalrule sanding is rst required.

The rack drawing inwardly on the floating lever opens the ports asalready described, but continues until at its inner end it engages thestem of the sanding valve.

'I'he opening of this valve means communication with the inlet annularchamber through a cross channel and this air passes through the portcustomarily closed by the sanding valve and down the sanding passage tothe sand box where it blows the sand on the rails.

The inward movement of the rack continues and the stem from the otherside of the sanding valve contacts with the stem of the emergency valvewhich opens a passage to the emergency pipe releasing the air underpressure in said pipe which flows out through the port covered by theemergency valve to the exhaust pipe.

The release of the air pressure from the emergency valve opens anauxiliary valve directly connecting the reservoir to the brake cylinderin quite another mechanism as is known in common practice.

It may be mentioned that the construction of the rack in this inventionis a very important feature, especially in the emergency application,for the rack is made in two pieces spring held together so that in theservice application, these pieces are practically intact and form onemoving part, while to continue the application to the emergencyapplication, the inner part may of itself separate itself from the headand continue to act without actually drawing the head with it, therebyleaving the stem pvot still in a service application position, whichmaintains the application coincidently and avoids any strain on theservice application in regard to high pressure.

What I claim isz- 1. In a self regulating fluid pressure valve, a valvebody divided into a valve chamber having an inlet port connected to asource of compressed air, an intermediate port connected to the work andan exhaust port, and a pressure adjusting chamber having an openconnection to the work, an actuating member suitably mounted in saidvalve body, a floating lever external to said valve body and exiblyconnected to said actuating member, a hollow valve having inlet andoutlet ports communicating with said inlet port and work port of thevalve chamber and associated with said floating lever and controllingthe ow of air to and from the work, and an adjusting member in saidpressure adjusting chamber and having a connection to said iloatinglever and adapted to return said Valve to its neutral position.

2. In a self regulating fluid pressure valve, a valve body divided intoa valve chamber having an inlet port connected to a source of compressedair, an intermediate port connected to the work and an exhaust port, anda pressure adjusting chamber having an open connection to the work, anactuating member suitably mounted in said valve body, a floating leverexternal to said valve body and flexibly connected to said actuatingmember, a valve in said valve chamber associated with said floatinglever and controlling the iow of air to and from the work, and anadjusting member in said pressure adjusting chamber comprising a headclosing said chamber, a diaphragm mounted on said head and a rodreciprocating in said head and connected to the inner end of saiddiaphragm and to said oating lever and adapted through the action ofsaid adjusting member to return said valve to its neutral position.

3. In a self regulating fluid pressure valve, a valve body divided intoan operating chamber having valve seats, a valve chamber having an inletport connected to a source of compressed air, an intermediate portconnected to the work and an exhaust port, and a pressure adjustingchamber having an open connection to the work, a sanding valve and anemergency valve in said operating chamber spring held to said seats, anactuating member in said operating chamber reciprocating said valves, afloating lever external to said valve body and flexibly to saidactuating member, a valve in said valve chamber associated with saidfloating lever and controlling the flow of air to and from the work, andan adjusting member in said pressure adjusting chamber and having aconnection to said floating lever and adapted to return the valve insaid valve chamber to its neutral position.

4. In a self regulating fluid pressure valve, a valve body divided intoan operating chamber having a valve seat, a valve chamber having aninlet port connected to a source of compressed air, an intermediate portconnected to the work and an exhaust port, and a pressure adjustingchamber having an open connection to the work, a sanding valve and anemergency valve in said operating chamber spring held tol said seats, arack in said operating chamber operable by a pinion reciprocating saidvalves, a floating lever external to said valve body and exiblyconnected to said rack, a valve in said valve chamber associated withsaid floating lever and controlling the flow of air to and from thework, and an adjusting member in said pressure adjusting chamber andhaving a connection to said floating lever and adapted to return `saidvalve to its neutral position.

ALBERT DEX HARRISON.

